FreeBSD 5.3 routing IPFW FWD'd packets?

[James R. Van Artsalen]

Achim Patzner wrote:

> Packets sent to the directly reachable net 192.168.254/8 (rule 64000) 
> seem to work.  Is it possible that packets are somehow being routed 
> after being FWD'd by IPFW?
>
> The counters show that the rule is applied, too. Just the "fwd" part 
> is not happening.


I'm suspicious of this code in netinet/ip_output.c:

#ifdef IPFIREWALL_FORWARD
...
        fwd_tag = m_tag_find(m, PACKET_TAG_IPFORWARD, NULL);
        if (fwd_tag) {
                if (!in_localip(ip->ip_src) && !in_localaddr(ip->ip_dst)) {
                        dst = (struct sockaddr_in *)&ro->ro_dst;
                        bcopy((fwd_tag+1), dst, sizeof(struct sockaddr_in));
                        m->m_flags |= M_SKIP_FIREWALL;
                        m_tag_delete(m, fwd_tag);
                        goto again;
                } else {
                        m_tag_delete(m, fwd_tag);
                        /* Continue. */
                }
        }
#endif

passout:

this seems to be where FWD is handled in this case.  The problem is that 
33 lines above I see this code:

        /* Jump over all PFIL processing if hooks are not active. */
        if (inet_pfil_hook.ph_busy_count == -1)
                goto passout;

It looks like me like IPFW forwarding isn't going to happen here unless 
there is some PFIL around.